Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c5257a5e63e4d62…

MALICIOUS

PDF

12.0 KB
MD5: 784b70423e9f6b898581e30c1eb9263a SHA-1: 0b033783923c9055211e3e62e9d037149cae1558 SHA-256: 4c5257a5e63e4d623b72735d861b41659443cf436bcb7f2fb1f37e98df7260c9
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious File

The PDF file contains embedded JavaScript, identified by multiple heuristics including 'PDF_JAVASCRIPT' and 'PDF_JS'. A critical heuristic, 'CVE_2007_5659', indicates the exploitation of a known vulnerability (Collab.collectEmailInfo) to execute a JavaScript stager. This stager is responsible for downloading and executing a second-stage payload, as suggested by the presence of large deobfuscated JavaScript files and the ClamAV detection signature 'Pdf.Exploit.Agent-36063'.

Heuristics 7

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36063 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36063
  • Annotation subject callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
eb39e2de4dbbc100de6d3e30aa43ff78fa075618862ba1ebba5151ea3a3b848d
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 273 bytes
annotation_subject_callee_hex_stage_000.js
b63e6d22efc035a6c787b8a198e45cbf03796814b8ee36770b6f9c6cf61b70f6
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5101 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
cb6982d9bd1e6759a5dfc78d214bf200026f6c458c7f72429946e39f6445d0c9
deobfuscated-js PDF JavaScript deobfuscation pass 81976 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).